Traffic signal



Nov. 4, 1941. F. A. LEDWARD 2,261,499

TRAFFI C S IGNAL Filed Nov. 18, 1940 2 sheets-sheet 1 Wei);

Frederick A. Lgd wand F. A. LEDWARD TR'AFFIG SIGNAL Nov. 4, 1941.

2 bneecs- Sheet 2' Filed Nov. 18, 1940 \hveflov Frederick A. Ledwaord -iI M ATTomv Patented Nov. 4, 1941 UNETED STATES PATENT OFFICE A TRAFFICSIGNAL Frederick A. Ledward, Grand Rapids, Mich.

Application November 18, 1940, Serial No. 366,034

3 Claims.

This invention relates generally to traffic signals and is particularlydirected to a means for indicating the portion of time each light is tooperate remains.

A particular object of the invention is the provision of indicatingmeans, preferably in the form of an arrow, which is rotatably mountedbetween ing means and an illumination of a light source during a portionof its rotative movement.

Other objects and purposes of th invention will appear more fully as thedescription proceeds.

To the accomplishment of the foregoing and related ends said invention,then, consists of the means hereinafter fully described and particularlypointed out in the claims.

The annexed drawings and following description set forth in detailcertain means for carrying out my invention, said means constituting,however, but one of various ways in which the principle of the inventionmay be employed.

In said annexed drawings wherein like reference numerals refer to likeparts throughout the various views:

Fig. 1 is a front elevation of the preferred form of my devic showingone of the arrows after it has rotated through a portion of itsrevolution.

Fig. 2 is a diagrammatic view showing the nanner in which the wiring islaid out.

Fig. 3 is a front elevatio showing the mechanism within the enclosure,and

Fig. 4 is a vertical section through the device from front to rear.

The main advantage arising out of this construction is the fact that itwill permit both motorists and pedestrians to know how long either thegreen or red light still has to operate before changing and willaccordingly enable the pedestrians particularly to know whether it isadvisable to proceed across the street or wait until the light haschanged back to green. It would also prevent pedestrians from beingcaught in the middle of the street when the light changes from green tored thereby reducing accidents as a result of such a situation.

Referring now more particularly to the drawings, it is to be seen that Iprovide an enclosure having a front I, a back 2, sides 3,and top andbottom 4 and 5 respectively. As isusual in traffie lights the front isprovided with upper and lower openings within which the red and greencolored glass 6 and l is located. The front may be either hingedlymounted on the enclosure or secured thereto in any other desired manner.

Spaced from the rear 2 is a board or partition 8 on which most of themechanism is mounted extending from the top to the bottom with variousopenings therein to enable the various parts of the mechanism to bemounted thereon.

In this board 8 are upper and lower openings 9 behind which and to therear side of the board are mounted the light sockets Ill so that thelight bulbs ll may extend therethrough. An additional plate 12 isprovided which has a shape substantially like that shown in Fig. 3. Thisplate is mounted on the board 8 and is secured thereto by any desiredmeans. In the center of the board 3 is another opening l3 which has amotor [4 located therein and which is provided with a shaft lfi'extending through the plate i2 and rotatably mounted therein. At theouter end of the shaft 15 and at the forward side of the plate a gearsegment I6 is secured and held in place by means of a collar ll. Theteeth on this gear segment extend substantiallyhalf way around it sothat in effect it is a semi-circular segment.

Openings are also provided in the plate l2 concentric With the openings9 in the board 8 and receive therein theshank ill of the gears l9. Aring 20 has a press fit around the shank l8 behind the mounting board toprevent removal of the gear I9 but permitting its rotation in theopeningin which it is mounted. The construction at the upper and lowerends of the plate l2 are similar. I

Immediately above the lower gear is and immediately below the upper oneanother gear .2!

is mounted for rotative movement in another opening in the place [2concentric with the open- 1 ings 22in the board 8. The gears 2| areadapted to be in mesh with the gears I9 so that a rotation of one willcause a rotation of the other in the opposite direction. At this point,then,

- it is to be noted that the respective locations of the various gearsis such that a clockwise rotation of the gear segment l6, when it is inmesh with the upper gear 2|, will cause a counterclockwise rotation ofthat gear which in turn will cause a clockwise rotation of the uppergear I9. Then as the gear segment continues to rotate one end willcontact the lower gear 2| as soon as the other end leaves the uppercorresponding gear and, through the same train, will cause a clockwiserotation of the lower gear I9. The gear segment is continuously rotatedby means of the motor I4 and therefore the upper and lower gears I9 willbe rotated automatically one complete revolution during one-half of arevolution of the gear segment and in alternate relation.

On each of the gears I9 an arm 23 is located which is curved slightlyand then extends forwardly to a point beyond the end of its adjacentlight source and an arrow 24 is mounted at the outer end thereof in sucha Way that a rotation of the gear I9 will also cause a clockwiserotation of its attached arrow 24 about the center of the gear as itsown rotative center. Since only one arrow and its corresponding light isin operation at one time, the light casts a shadow of the arrow on thecolored glass in front thereof and, since it is known that one lightwill be extinguished and the other one illuminated as soon as the arrowreaches its upper vertical position, a pedestrian or motorist will beable to tell at a glance how soon the traflic signal will change.

Another feature of my invention is the provision of means to cause thechanging of the lights also by movement of the gear segment I6 whichcauses a changing of the movement of the arrows. To effect this result,I provide adjacent each light source a pair of brackets 25 one on eitherside of the gear 2I between which extends a partial enclosure 26.Adjacent this small enclosure 26 is a metallic spring bar 21 secured atone end to the partition 8 and at its other end carrying the electricwire 28. The other corresponding wire 29 has its end bared and islocated Within the enclosure 26 adjacent the end of the wire 28. The bar21 has sufficient tension therein and is so located that it normallymaintains the ends of the two wires 28 and 29 spaced apart. Thisconstruction constitutes a switch so that when the switch is closed byforcing a contact between the ends of the two wires 28 and 29 it willlight the adjacent light source.

The end of the tension bar 21 has an enlargement 30 thereon throughwhich the Wire 23 passes and the gear segment I6 has a camming rib 3|thereon so that in its rotative movement it will contact first one andthen the other end 30 of each spring 21 forcing the end of the wire 28against the end 29 thereby closing the circuit and lighting the light.It is to be noted that these various switches are located with respectto each gear 21 so that as one end of the gear segment causes a rotationof an arrow it simultaneously lights the light which casts the shadow ofthat arrow onto the glass in front thereof. The wiring diagram of theseswitches and associated parts is shown in Fig. 2.

While I have here illustrated and described what I consider to be thepreferred form of my invention it is to be understood that certain partsthereof such as the arrows may be changed to other indicating means, andother parts so changed without departing in any way from the spirit ofthe invention. It should also be noted here that I have preferred toprovide a reflector 32 around each light source to not only concentratethe light and make the shadow of the arrow more clear and distinct butalso to prevent any light from one light source being seen through theopposite opening in the front of the enclosure.

This invention will be especially advantageous for pedestrians byenabling them to know how much more time will elapse before the lightchanges from green to red, and it will also aid motorists in the sameway. The device is simple and economical to manufacture and has operatedsatisfactorily in practice.

Other modes of applying the principle of my invention may be usedinstead of the one here described, change being made as regards thestructure herein disclosed provided, however, that the means stated byany of the following claims or the equivalent of such stated means beemployed.

I, therefore, particularly point out and distinctly claim, as myinvention:

1. A traffic signal comprising, an enclosure, two light sources mountedwithin said enclosure one above the other, a front on said enclosurehaving openings therein opposite said light sources, a gear surroundingeach light source, a second gear above and below the lower and upperfirst gears respectively, a continuously rotating semi-circular gearsegment mounted between said second gears and driving them alternately,a switch adjacent each light source to illuminate each one when itscorresponding switch is closed, camming means on said gear segment toclose each switch alternately as said segment is rotated, and an arrowin front of each light source mounted on the adjacent first mentionedgear and rotatable therewith, whereby said gear segment will cause anillumination of each light source and a complete rotation of the arrowadjacent thereto alternately during each complete rotation of saidsegment.

2. A traffic signal comprising, an enclosure, two light sources mountedwithin said enclosure one above the other, a front on said enclosurehaving openings therein opposite said light sources, a semi-circulargear segment mounted between said light sources, means to rotate saidsegment continuously, an electric switch adjacent each light source,means on said segment to close said switches alternately to illuminateeach light source during one half of a revolution thereof, an arrow infront of each light source, and means on which each arrow is mounted tocause a complete revolution of each; arrow while the light sourceadjacent thereto is illuminated.

3. The combination of elements defined in claim 2, wherein said lastnamed means is actuated by said gear segment.

FREDERICK A. LEDWARD.

